code: def OnWhiz(self, event):
      self.x += np.pi / 15
      self.y += np.pi / 20
      z = np.sin(self.x) + np.cos(self.y)
      self.im.set_array(z)
  
      zmax = np.max(z) - ERR_TOL
      ymax_i, xmax_i = np.nonzero(z >= zmax)
      if self.im.origin == "upper":
          ymax_i = z.shape[0] - ymax_i
      self.lines[0].set_data(xmax_i, ymax_i)
  
      self.canvas.draw()
  
file_path: matplotlib/galleries/examples/user_interfaces/embedding_in_wx3_sgskip.py
imports: import wx
  import wx.xrc
  import numpy
  from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg
  from matplotlib.backends.backend_wxagg import NavigationToolbar2WxAgg
  import matplotlib.cbook
  import matplotlib.cm
  from matplotlib.figure import Figure
label_desc: Use image node_id 4 for calling the PlotPanel obj's underlying member method code with example usage: obj.OnWhiz(event) without return types